The hematological and serum biochemical profiles of apparently healthy exotic breed of dogs in Jos, Plateau state, Nigeria was studied in this research. One hundred and seven exotic breed of dogs were examined from Oc...The hematological and serum biochemical profiles of apparently healthy exotic breed of dogs in Jos, Plateau state, Nigeria was studied in this research. One hundred and seven exotic breed of dogs were examined from October</span><span style="font-family:""> - </span><span style="font-family:"">December, 2018. The results from physical, clinical examinations and parasitological examinations were used to determine ap</span><span style="font-family:Verdana;"></span><span style="font-family:"">parently healthy exotic breed of dogs which were used in this study. The parameters measured were rectal temperature, parasitaemia, hematology which included red blood cells count, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin and hemoglobin content;total white blood cell count, including eosinophils, neutrophils, lymphocytes, monocytes, granulocytes counts, and platelets;serum biochemical parameters also included Aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, total proteins, albumin, globulin, blood urea nitrogen, creatinine, cholesterol and triglyceride, using standard methods. Data generated from the study were statistically analyzed using students t</span><span style="font-family:"">-</span><span style="font-family:"">test one-way analysis of variance while the level of significance </span><span style="font-family:"">was </span><span style="font-family:"">measured at p < 0.05. From this study, hematological and serum biochemical values were comparable to and not different from those reported for dogs in available literature, but the upper and lower reference limits (minimum and maximum values) were different for most parameters. Sex-related significant difference (p < 0.05) occurred only in WBC and total protein while age-related significant difference occurred only in total protein and urea level. Breed affected the MCHC and total bilirubin level which was evident in higher MCHC level in Neapolitan mastiff than Alsatian breed while total bilirubin was higher in Alsatian breed than Bull mastiff (p < 0.05). The present study has presented preliminary information on the range of hematological and serum biochemistry profile of exotic breed of dogs in Jos, Plateau state, Nigeria which may be useful to biomedical researchers and veterinary clinicians.展开更多
It is reckoned worldwide that verocytotoxigenic Escherichia coli (VTEC) serotypes are important food borne pathogens causing severe health problems in humans. A cross sectional epidemiological study was carried out to...It is reckoned worldwide that verocytotoxigenic Escherichia coli (VTEC) serotypes are important food borne pathogens causing severe health problems in humans. A cross sectional epidemiological study was carried out to determine the prevalence of VTEC serotypes (O157 and non O157) in both apparently healthy and diarrhoeic cattle in Abuja, FCT. A total of 718 faecal samples collected from abattoirs and cattle herds from Abuja, FCT representing 381 from apparently healthy and 337 from diarrhoeic cattle were analyzed. Primary isolation of typical E. coli was done using Eosin Methylene Blue (EMB) agar and performing biochemical tests. Samples were further analyzed using Cefixime, Tellurite-Sorbitol McConkey (CT-SMAC) agar to identify sorbitol and non sorbitol fermenting E. coli. Further characterization of both the sorbitol fermenting and non sorbitol fermenting E. coli was done using commercially procured latex agglutination test kits from Oxoid, United Kingdom. The prevalence of VTEC O157 in apparently healthy cattle was 1.84% and 2.96% for diarrhoeic cattle while the prevalence of non O157 VTEC was 3.67% and 7.12% for apparently healthy and diarrhoeic cattle respectively. There was no strong association (p > 0.05) between faecal consistency and infection with VTEC O157. A strong association (p < 0.05) however existed between faecal consistency and infection with non-O157 VTEC. Diarrhoeic cattle appear likely to be more affected. The implication of the study is that individuals in contact with cattle such as veterinarians, abattoir workers and cattle herdsmen are at risk of exposure to VTEC and proper hygienic control measures should be adopted.展开更多
Using a dynamic laser monitoring technique,the solubility of 3-nitro-1,2,4-triazole-5-one(NTO)was investigated in two different binary systems,namely hydroxylamine nitrate(HAN)-water and boric acid(HB)-water ranging f...Using a dynamic laser monitoring technique,the solubility of 3-nitro-1,2,4-triazole-5-one(NTO)was investigated in two different binary systems,namely hydroxylamine nitrate(HAN)-water and boric acid(HB)-water ranging from 278.15 K to 318.15 K.The solubility in each system was found to be positively correlated with temperature.Furthermore,solubility data were analyzed using four equations:the modified Apelblat equation,Van’t Hoff equation,λh equation and CNIBS/R-K equations,and they provided satisfactory results for both two systems.The average root-mean-square deviation(105RMSD)values for these models were less than 13.93.Calculations utilizing the Van’t Hoff equation and Gibbs equations facilitated the derivation of apparent thermodynamic properties of NTO dissolution in the two systems,including values for Gibbs free energy,enthalpy and entropy.The%ζ_(H)is larger than%ζ_(TS),and all the%ζ_(H)data are≥58.63%,indicating that the enthalpy make a greater contribution than entropy to theΔG_(soln)^(Θ).展开更多
Earthquakes are caused directly by the motion of the stress field,therefore,observing the stress field is significant.Experiments on the relationships among wave velocity,stress factors,and faults show that the wave v...Earthquakes are caused directly by the motion of the stress field,therefore,observing the stress field is significant.Experiments on the relationships among wave velocity,stress factors,and faults show that the wave velocity of rock media under stable stress fields corresponds one-to-one with stress factors.Therefore,the wave velocity gradient can indicate the direction of stress vector,and the gradient divergence can indicate the strength of the stress field.To verify the results,considering the limitations of wave velocity measurement in solid crustal media,two quantities,namely the apparent wave velocity and Poisson ratios relating to wave velocity,were used to refl ect the stress field state.The seismic data of the Tangshan and Luzhou regions were studied separately.The calculated apparent wave velocity and Poisson ratios were interpolated to achieve regional data gridding.The gradients and the gradient divergences of the apparent wave velocity and Poisson ratio fields in the two regions were analyzed,and it was found that their spatial distribution in the same region was the same.They are believed to refl ect the vertical projection of the stress direction vector and strength on the surface in the stress field,consistent with the experimental results.Whether it can eff ectively refl ect the stress field requires further analysis of the specific situation of the local medium and the movement mode of the stress field.展开更多
Peanut varieties are diverse globally,with their characters and nutrition determining the product quality.However,the comparative analysis and statistical analysis of key quality indicators for peanut kernels across t...Peanut varieties are diverse globally,with their characters and nutrition determining the product quality.However,the comparative analysis and statistical analysis of key quality indicators for peanut kernels across the world remains relatively limited,impeding the comprehensive evaluation of peanut quality and hindering the industry development on a global scale.This study aimed to compare and analyze the apparent morphology,microstructure,single-cell structure,engineering and mechanical properties,as well as major nutrient contents of peanut kernels from 10 different cultivars representing major peanut-producing countries.The surface and cross-section microstructure of the peanut kernels exhibited a dense“blocky”appearance with a distinct cellular structure.The lipid droplets were predominantly spherical with a regular distribution within the cells.The single-cell structure of the kernels from these 10 peanut cultivars demonstrated varying morphologies and dimensions,which exhibited correlations with their mechanical and engineering properties.Furthermore,the mass loss versus temperature profiles of the peanut kernels revealed five distinct stages,corresponding to moisture loss,volatile loss,protein denaturation,and the degradation of various biomacromolecules.Variations were also observed in the lipid,protein,and sucrose contents,texture,bulk density,true density,porosity,geometric mean diameter,and sphericity among the diferent peanut varieties.This study establishes relationships and correlations among microstructure,engineering properties,and nutritional composition of commonly grown peanut varieties in major peanut-processing countries.The findings provide valuable insights into peanut quality evaluation,empowering the peanut industry to enhance their processing and product development efforts.展开更多
The study focuses on the filling of pods from ten cacao clones originating from French Guiana in Côte d’Ivoire. Two reference clones (IFC5 and NA32) were used as controls. The parameters studied include the numb...The study focuses on the filling of pods from ten cacao clones originating from French Guiana in Côte d’Ivoire. Two reference clones (IFC5 and NA32) were used as controls. The parameters studied include the number of ovules per ovary, the average number of beans per pod, the fresh bean weight, and the pod index. The aim was to evaluate the genetic variability and agronomic performance of these clones under natural pollination conditions. The results show significant genetic variability between the clones for all traits studied. The IFC5 clone, known for its excellent pod filling, exhibited the highest apparent fertility (0.91), while the GU183/A clone had the lowest filling (0.47). Three types of distributions of the number of beans per pod were identified: a right-skewed unimodal distribution, characteristic of well-filled clones;a left-skewed unimodal distribution, associated with poorly filled clones;and an intermediate bimodal distribution. These differences could be related to pollination compatibility and the availability of compatible pollen. Regarding the fresh bean weight and pod index, the GU183/A clone stood out with the heaviest beans (3.27 g) but had a high pod index (49.58), indicating relatively low productivity. None of the Guyanese clones achieved the filling level of the IFC5 clone, although some surpassed the NA32 control. This study highlights the importance of apparent fertility and the number of beans per pod as essential criteria for cacao genetic improvement programs. The authors recommend extending research to a larger number of Guyanese clones and exploring complementary traits, such as the influence of pollination type and intergroup compatibility.展开更多
Taking the Qihe area as an example,this paper compared various geophysical exploration methods in view of the problems of urban construction,deep thermal reservoir burial,and vast overlying low-resistance shield layer...Taking the Qihe area as an example,this paper compared various geophysical exploration methods in view of the problems of urban construction,deep thermal reservoir burial,and vast overlying low-resistance shield layer in deep karst geothermal exploration.A Controlledsource audio magnetotelluric(CSAMT)method was taken to overcome the problems and detect deep stratigraphic structures in the study area.The acquisition parameters of CSAMT were optimized to take into account the exploration depth and signal-to-noise ratio.The distortion of data in the near and transition zone was eliminated by the inversion of equivalent whole-region apparent resistivity,so as to achieve the purpose of deep sounding.Based on the resistivity profile resulting from the proposed CSAMT method,three faults were inferred and one low-resistance anomaly zone in the area was traced.The results of the profile interpretation were verified by drilling.The inferred stratigraphic boundaries and low-resistance anomaly zone were basically in agreement with the drilling results,thereby proving the eff ectiveness of the CSAMT method for deep geothermal exploration in low-resistance coverage areas.This method could provide technical support for deep geothermal exploration in similar areas.展开更多
Insect herbivory is ubiquitous in various ecosystems,and directly influences the growth and survival of individual plants,especially during their vulnerable early life stages like the seedling phase.This,in turn,exert...Insect herbivory is ubiquitous in various ecosystems,and directly influences the growth and survival of individual plants,especially during their vulnerable early life stages like the seedling phase.This,in turn,exerts a significant influence on forest community diversity and structure,as well as ecosystem function and stability.Notable variation in herbivory has been detected both among and within plant species.For decades,many hypotheses have been proposed to explain such variations,including both biotic and abiotic variables.However,most studies have considered only one or several of these hypotheses by focusing on a few potential variables,and their results were usually inconsistent;thus,the factors driving herbivory remain unclear.In this study,we examined leaf herbivory by insects of woody species seedlings in a subtropical forest in southwestern China over two seasons.In total,24 potential variables that represented abiotic resource availability,characters of individual seedlings,conspecific and heterospecific species,and the whole seedling community were selected to test several commonly discussed alternative herbivory hypotheses.Overall,our findings showed that the plant apparency hypothesis was more supported than the other hypotheses in explaining insect seedling herbivory.Our results further indicated that the mechanisms and causes of insect herbivory are complex,multifactorial,species-specific and vary with seasons,indicating that there may be no uniform rules in explaining herbivory for all seedlings.Consequently,such complexity may play an important role in promoting species coexistence and biodiversity maintenance in seedling communities,which may further translate into the following generation of saplings or even adult communities.Changes in the community of insect herbivores and/or variables influencing insect herbivory,may disrupt stability of the original seedling community,thus affecting the regeneration and development of the entire forest community.Therefore,we suggest that issues related to insect herbivory should be considered when developing forest management and conservation.展开更多
Background Scant information is currently available on the use of insect oils in ruminant diets.Insect oils could be used as alternatives to certain conventional plant lipid sources that are considered no longer susta...Background Scant information is currently available on the use of insect oils in ruminant diets.Insect oils could be used as alternatives to certain conventional plant lipid sources that are considered no longer sustainable.This trial aims at evaluating the effects of the dietary inclusion of Hermetia illucens oil(HIO)vs.hydrogenated palm fat(HPF)on digestive parameters,oxidative stress,and milk production performance of dairy cows.Results Twenty-six Valdostana Red Pied cows were randomly divided into two groups and fed with hay ad libitum and a concentrate containing 3%(as fed)of either HPF or HIO.The trial lasted 50 d,including two weeks of diet adaptation.Individual feed intake and milk yield were monitored three and four times a week,respectively.Fecal samples were collected at the end(d 50)of the trial to determine total-tract nutrients apparent digestibility.Individual blood samples were collected to evaluate blood plasma metabolites(d 0 and d 50)and oxidative stress parameters(d 0,d 26 and d 50).Milk samples were collected at d 0,d 14,d 26,d 38 and d 50 for chemical composition analysis.Feed efficiency was estimated through feed conversion ratio and residual feed intake(RFI).Data were analyzed by SAS software using a mixed model.The diet had no effect on nutrients intake and apparent total-tract digestibility.However,the dietary inclusion of HIO led to higher milk production(+0.82 kg/cow/d;P<0.05)and slightly lower RFI(−0.008;P<0.001)when compared to the HPF diet.Milk composition and the nutritional metabolic status of the cows remained unaffected by diet.Serum antioxidant capacity was comparable between the two groups,while lower derivatives of reactive oxygen metabolite concentrations were observed in the HIO-fed cows when compared to the HPF-fed ones(−37.13 Carratelli Units;P<0.001).Conclusions The dietary inclusion of HIO instead of HPF did not negatively affect feed palatability and total-tract apparent digestibility of nutrients in dairy cows.Furthermore,it increased feed efficiency by supporting a higher milk production together with an improved antioxidant status.The results suggest that HIO could be an eligible option as an innovative energy source for dairy cows.展开更多
The article discusses the use of pulse-width modulation signals to generate low-temperature atmospheric plasma in an inert gas environment.The results of studies of the energy consumption of a low-temperature plasma g...The article discusses the use of pulse-width modulation signals to generate low-temperature atmospheric plasma in an inert gas environment.The results of studies of the energy consumption of a low-temperature plasma generation system depending on the duty rate,as well as the pulse repetition rate,are presented.The operating modes of the system have been established,in which a minimum of energy consumption is achieved.The issues of evaluating the interaction of plasma with objects based on the analysis of changes in signal parameters in the high-voltage circuit of the generator are also considered.展开更多
The discovery of high-temperature superconductivity in La_(3)Ni_(2)O_(7) and La_(4)Ni_(3)O_(10) under pressure has garnered extensive attention.Herein,we report systematic investigations on the structure,magnetism,and...The discovery of high-temperature superconductivity in La_(3)Ni_(2)O_(7) and La_(4)Ni_(3)O_(10) under pressure has garnered extensive attention.Herein,we report systematic investigations on the structure,magnetism,and electrical resistance evolutions of Pr_(4)Ni_(3)O_(10−δ)polycrystalline samples under various pressures.Pr_(4)Ni_(3)O_(10−δ)exhibits density wave transitions on Ni and Pr sublattices at approximately 157.6 and 4.3 K,respectively.The density wave can be progressively suppressed by pressure.A structural transformation from the monoclinic P21/a space group to the tetragonal I4/mmm occurs around 20GPa.An apparent drop in resistance with an evident magnetic field dependence is observed at pressures above 20GPa,indicating the emergence of superconductivity.The discovery of superconductivity in Pr_(4)Ni_(3)O_(10−δ)broadens the family of nickelate superconductors.Pr_(4)Ni_(3)O_(10−δ)provides a new platform for investigation of the mechanisms of superconductivity in the Ruddlesden-Popper phases of nickelates.展开更多
Catastrophic geological disasters frequently occur on slopes with obliquely inclined bedding structures(also referred to as obliquely inclined bedding slopes),where the apparent dip sliding is not readily visible.This...Catastrophic geological disasters frequently occur on slopes with obliquely inclined bedding structures(also referred to as obliquely inclined bedding slopes),where the apparent dip sliding is not readily visible.This phenomenon has become a focal point in landslide research.Yet,there is a lack of studies on the failure modes and mechanisms of hidden,steep obliquely inclined bedding slopes.This study investigated the Shanyang landslide in Shaanxi Province,China.Using field investigations,laboratory tests of geotechnical parameters,and the 3DEC software,this study developed a numerical model of the landslide to analyze the failure process of such slopes.The findings indicate that the Shanyang landslide primarily crept along a weak interlayer under the action of gravity.The landslide,initially following a dip angle with the support of a stable inclined rock mass,shifted direction under the influence of argillization in the weak interlayer,moving towards the apparent dip angle.The slide resistance effect of the karstic dissolution zone was increasingly significant during this process,with lateral friction being the primary resistance force.A reduction in the lateral friction due to karstic dissolution made the apparent dip sliding characteristics of the Shanyang landslide more pronounced.Notably,deformations such as bending and uplift at the slope’s foot suggest that the main slide resistance shifts from lateral friction within the karstic dissolution zone to the slope foot’s resistance force,leading to the eventual buckling failure of the landslide.This study unveils a novel failure mode of apparent dip creep-buckling in the Shanyang landslide,highlighting the critical role of lateral friction from the karstic dissolution zone in its failure mechanism.These insights offer a valuable reference for mitigating risks and preventing disasters related to obliquely inclined bedding landslides.展开更多
Bone tissue renewal can be enhanced through co-transplantation of bone mesenchymal stem cells(BMSCs)and vascular endothelial cells(ECs).However,there are apparent limitations in stem cell-based therapy which hinder it...Bone tissue renewal can be enhanced through co-transplantation of bone mesenchymal stem cells(BMSCs)and vascular endothelial cells(ECs).However,there are apparent limitations in stem cell-based therapy which hinder its clinic translation.Hence,we investigated the potential of alternative stem cell substitutes for facilitating bone regeneration.In this study,we successfully prepared cell membrane vesicles(CMVs)from BMSCs and ECs.The results showed that BMSC-derived cell membrane vesicles(BMSC-CMVs)possessed membrane receptors involved in juxtacrine signaling and growth factors derived from their parental cells.EC-derived cell membrane vesicles(EC-CMVs)also contained BMP2 and VEGF derived from their parental cells.BMSC-CMVs enhanced tube formation and migration ability of hUVECs,while EC-CMVs promoted the osteogenic differentiation of hBMSCs in vitro.Using a rat skull defect model,we found that co-transplantation of BMSC-CMVs and EC-CMVs could stimulate angiogenesis and bone formation in vivo.Therefore,our research might provide an innovative and feasible approach for cell-free therapy in bone tissue regeneration.展开更多
The creation of controlled-release urea (CRU) is a potent substitute for conventional fertilizers in order to preserve the availability of nitrogen (N) in soil,prevent environmental pollution,and move toward green agr...The creation of controlled-release urea (CRU) is a potent substitute for conventional fertilizers in order to preserve the availability of nitrogen (N) in soil,prevent environmental pollution,and move toward green agriculture.The main objectives of this study were to assess the impacts of CRU’s full application on maize production and to clarify the connection between the nutrient release pattern of CRU and maize nutrient uptake.In order to learn more about the effects of CRU application on maize yields,N uptake,mineral N (N_(min)) dynamics,N balance in soil-crop systems,and economic returns,a series of field experiments were carried out in 2018–2020 in Dalian City,Liaoning Province,China.There were 4 different treatments in the experiments:no N fertilizer input (control,CK);application of common urea at 210 kg ha^(-1)(U),the ideal fertilization management level for the study site;application of polyurethane-coated urea at the same N input rate as U (PCU);and application of PCU at a 20% reduction in N input rate (0.8PCU).Our findings showed that using CRU (i.e.,PCU and 0.8 PCU) may considerably increase maize N absorption,maintain maize yields,and increase N use efficiency (NUE) compared to U.The grain yield showed considerable positive correlations with total N uptake in leaf in U and 0.8 PCU,but negative correlations with that in PCU,indicating that PCU caused excessive maize absorption while 0.8 PCU could achieve a better yield response to N supply.Besides,PCU was able to maintain N fertilizer in the soil profile 0–20 cm away from the fertilization point,and higher N_(min)content was observed in the 0–20 cm soil layer at various growth stages,particularly at the middle and late growing stages,optimizing the temporal and spatial distributions of N_(min).Additionally,compared to that in U,the apparent N loss rate in PCU was reduced by 36.2%,and applying CRU (PCU and 0.8 PCU) increased net profit by 8.5% to 15.2% with less labor and fertilization frequency.It was concluded that using CRU could be an effective N fertilizer management strategy to sustain maize production,improve NUE,and increase economic returns while minimizing environmental risks.展开更多
Stress-dependent permeability models are developed for the organic pores and inorganic cleats/fractures in unconventional gas reservoirs,which are modeled as Biot’s porous media of dual-porosity.Further considering m...Stress-dependent permeability models are developed for the organic pores and inorganic cleats/fractures in unconventional gas reservoirs,which are modeled as Biot’s porous media of dual-porosity.Further considering multiple flow mechanisms such as dynamic effects of gas flow and surface diffusion,apparent permeability models are obtained to investigate the characteristics of unconventional gas migration.Compared to the gas transfer in single-porosity reservoirs,the gas migration ability of cleats in dual-porosity stratums rarely changes while that of organic pores is greatly improved because cleats sustain major geomechanical shrinkage deformation when the pore pressure drops.Further,the mass flux of reservoirs is dominated by the mass flux of cleats,which has a lower peak value,but a much longer production term than those in single-porosity reservoirs due to the interaction between organic pores and cleats.Parametric analysis is conducted to identify key factors significantly impacting mass flux in unconventional reservoirs.Reasons for the mass flux variation are also explored in terms of gas migration ability and pore pressure distribution.展开更多
Prostate cancer(PCa)imaging forms an important part of PCa clinical management.Magnetic resonance imaging is the modality of choice for prostate imaging.Most of the current imaging assessment is qualitative i.e.,based...Prostate cancer(PCa)imaging forms an important part of PCa clinical management.Magnetic resonance imaging is the modality of choice for prostate imaging.Most of the current imaging assessment is qualitative i.e.,based on visual inspection and thus subjected to inter-observer disagreement.Quantitative imaging is better than qualitative assessment as it is more objective,and standardized,thus improving interobserver agreement.Apart from detecting PCa,few quantitative parameters may have potential to predict disease aggressiveness,and thus can be used for prognosis and deciding the course of management.There are various magnetic resonance imaging-based quantitative parameters and few of them are already part of PIRADS v.2.1.However,there are many other parameters that are under study and need further validation by rigorous multicenter studies before recommending them for routine clinical practice.This review intends to discuss the existing quantitative methods,recent developments,and novel techniques in detail.展开更多
Oil transport is greatly affected by heterogeneous pore–throat structures present in shale.It is therefore very important to accurately characterize pore–throat structures.Additionally,it remains unclear how pore–t...Oil transport is greatly affected by heterogeneous pore–throat structures present in shale.It is therefore very important to accurately characterize pore–throat structures.Additionally,it remains unclear how pore–throat structures affect oil transport capacity.In this paper,using finite element(FE)simulation and mathematical modeling,we calculated the hydrodynamic resistance for four pore–throat structure.In addition,the influence of pore throat structure on shale oil permeability is analyzed.According to the results,the hydrodynamic resistance of different pore throat structures can vary by 300%.The contribution of additional resistance caused by streamline bending is also in excess of 40%,even without slip length.Fur-thermore,Pore–throat structures can affect apparent permeability by more than 60%on the REV scale,and this influence increases with heterogeneity of pore size distribution,organic matter content,and organic matter number.Clearly,modeling shale oil flow requires consideration of porous–throat structure and additional resistance,otherwise oil recovery and flow capacity may be overestimated.展开更多
Lightweight refractories for the working lining of high-temperature furnaces play an important role in the smelting of advanced steels and superalloys.To prepare lightweight refractories for the working lining of high...Lightweight refractories for the working lining of high-temperature furnaces play an important role in the smelting of advanced steels and superalloys.To prepare lightweight refractories for the working lining of high-temperature furnaces,the synthesis of lightweight aggregates is the basis.Recently,the research on the synthesis of lightweight aggregates with high service temperature,low thermal conductivity,high strength,and good slag resistance has received widespread attention.The available literature on the synthesis of lightweight aggregates was summarized,including corundum,mullite,mullite-corundum,spinel,corundum-spinel,cordierite,cordierite-mullite,calcium hexaluminate,corundum-calcium hexaluminate,bauxite,magnesia,magnesia-based,and forsterite-based aggregates.Finally,the future development trend of lightweight aggregates was proposed.展开更多
Using the typical characteristics of multi-layered marine and continental transitional gas reservoirs as a basis,a model is developed to predict the related well production rate.This model relies on the fractal theory...Using the typical characteristics of multi-layered marine and continental transitional gas reservoirs as a basis,a model is developed to predict the related well production rate.This model relies on the fractal theory of tortuous capillary bundles and can take into account multiple gas flow mechanisms at the micrometer and nanometer scales,as well as the flow characteristics in different types of thin layers(tight sandstone gas,shale gas,and coalbed gas).Moreover,a source-sink function concept and a pressure drop superposition principle are utilized to introduce a coupled flow model in the reservoir.A semi-analytical solution for the production rate is obtained using a matrix iteration method.A specific well is selected for fitting dynamic production data,and the calculation results show that the tight sandstone has the highest gas production per unit thickness compared with the other types of reservoirs.Moreover,desorption and diffusion of coalbed gas and shale gas can significantly contribute to gas production,and the daily production of these two gases decreases rapidly with decreasing reservoir pressure.Interestingly,the gas production from fractures exhibits an approximately U-shaped distribution,indicating the need to optimize the spacing between clusters during hydraulic fracturing to reduce the area of overlapping fracture control.The coal matrix water saturation significantly affects the coalbed gas production,with higher water saturation leading to lower production.展开更多
Due to the instability of FeO at temperatures below 843 K,the fuidization reduction pathway of iron ore powder changes with the reduction temperature.Thus,the effect of temperature and reaction pathway interaction on ...Due to the instability of FeO at temperatures below 843 K,the fuidization reduction pathway of iron ore powder changes with the reduction temperature.Thus,the effect of temperature and reaction pathway interaction on the kinetics of fuidization reduction of iron ore powder under low-temperature conditions ranging from 783 to 903 K was investigated to describe the fluidization reduction rate of iron ore powder from three aspects:microstructure change,reaction limiting link,and apparent activation energy of the reaction,exploring their internal correlation.The experimental results revealed that in a temperature range of 783-813 K,the formation of a dense iron layer hindered the internal diffusion of reducing gas,resulting in relatively high gas diffusion resistance.In addition,due to the differences in limiting links and reaction pathways in the intermediate stage of reduction,the apparent activation energy of the reaction varied.The apparent activation energy of the reaction ranged from 23.36 to 89.13 kJ/mol at temperature ranging from 783 to 813 K,while it ranged from 14.30 to 68.34 kJ/mol at temperature ranging from 873 to 903 K.展开更多
文摘The hematological and serum biochemical profiles of apparently healthy exotic breed of dogs in Jos, Plateau state, Nigeria was studied in this research. One hundred and seven exotic breed of dogs were examined from October</span><span style="font-family:""> - </span><span style="font-family:"">December, 2018. The results from physical, clinical examinations and parasitological examinations were used to determine ap</span><span style="font-family:Verdana;"></span><span style="font-family:"">parently healthy exotic breed of dogs which were used in this study. The parameters measured were rectal temperature, parasitaemia, hematology which included red blood cells count, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin and hemoglobin content;total white blood cell count, including eosinophils, neutrophils, lymphocytes, monocytes, granulocytes counts, and platelets;serum biochemical parameters also included Aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, total proteins, albumin, globulin, blood urea nitrogen, creatinine, cholesterol and triglyceride, using standard methods. Data generated from the study were statistically analyzed using students t</span><span style="font-family:"">-</span><span style="font-family:"">test one-way analysis of variance while the level of significance </span><span style="font-family:"">was </span><span style="font-family:"">measured at p < 0.05. From this study, hematological and serum biochemical values were comparable to and not different from those reported for dogs in available literature, but the upper and lower reference limits (minimum and maximum values) were different for most parameters. Sex-related significant difference (p < 0.05) occurred only in WBC and total protein while age-related significant difference occurred only in total protein and urea level. Breed affected the MCHC and total bilirubin level which was evident in higher MCHC level in Neapolitan mastiff than Alsatian breed while total bilirubin was higher in Alsatian breed than Bull mastiff (p < 0.05). The present study has presented preliminary information on the range of hematological and serum biochemistry profile of exotic breed of dogs in Jos, Plateau state, Nigeria which may be useful to biomedical researchers and veterinary clinicians.
文摘It is reckoned worldwide that verocytotoxigenic Escherichia coli (VTEC) serotypes are important food borne pathogens causing severe health problems in humans. A cross sectional epidemiological study was carried out to determine the prevalence of VTEC serotypes (O157 and non O157) in both apparently healthy and diarrhoeic cattle in Abuja, FCT. A total of 718 faecal samples collected from abattoirs and cattle herds from Abuja, FCT representing 381 from apparently healthy and 337 from diarrhoeic cattle were analyzed. Primary isolation of typical E. coli was done using Eosin Methylene Blue (EMB) agar and performing biochemical tests. Samples were further analyzed using Cefixime, Tellurite-Sorbitol McConkey (CT-SMAC) agar to identify sorbitol and non sorbitol fermenting E. coli. Further characterization of both the sorbitol fermenting and non sorbitol fermenting E. coli was done using commercially procured latex agglutination test kits from Oxoid, United Kingdom. The prevalence of VTEC O157 in apparently healthy cattle was 1.84% and 2.96% for diarrhoeic cattle while the prevalence of non O157 VTEC was 3.67% and 7.12% for apparently healthy and diarrhoeic cattle respectively. There was no strong association (p > 0.05) between faecal consistency and infection with VTEC O157. A strong association (p < 0.05) however existed between faecal consistency and infection with non-O157 VTEC. Diarrhoeic cattle appear likely to be more affected. The implication of the study is that individuals in contact with cattle such as veterinarians, abattoir workers and cattle herdsmen are at risk of exposure to VTEC and proper hygienic control measures should be adopted.
文摘Using a dynamic laser monitoring technique,the solubility of 3-nitro-1,2,4-triazole-5-one(NTO)was investigated in two different binary systems,namely hydroxylamine nitrate(HAN)-water and boric acid(HB)-water ranging from 278.15 K to 318.15 K.The solubility in each system was found to be positively correlated with temperature.Furthermore,solubility data were analyzed using four equations:the modified Apelblat equation,Van’t Hoff equation,λh equation and CNIBS/R-K equations,and they provided satisfactory results for both two systems.The average root-mean-square deviation(105RMSD)values for these models were less than 13.93.Calculations utilizing the Van’t Hoff equation and Gibbs equations facilitated the derivation of apparent thermodynamic properties of NTO dissolution in the two systems,including values for Gibbs free energy,enthalpy and entropy.The%ζ_(H)is larger than%ζ_(TS),and all the%ζ_(H)data are≥58.63%,indicating that the enthalpy make a greater contribution than entropy to theΔG_(soln)^(Θ).
文摘Earthquakes are caused directly by the motion of the stress field,therefore,observing the stress field is significant.Experiments on the relationships among wave velocity,stress factors,and faults show that the wave velocity of rock media under stable stress fields corresponds one-to-one with stress factors.Therefore,the wave velocity gradient can indicate the direction of stress vector,and the gradient divergence can indicate the strength of the stress field.To verify the results,considering the limitations of wave velocity measurement in solid crustal media,two quantities,namely the apparent wave velocity and Poisson ratios relating to wave velocity,were used to refl ect the stress field state.The seismic data of the Tangshan and Luzhou regions were studied separately.The calculated apparent wave velocity and Poisson ratios were interpolated to achieve regional data gridding.The gradients and the gradient divergences of the apparent wave velocity and Poisson ratio fields in the two regions were analyzed,and it was found that their spatial distribution in the same region was the same.They are believed to refl ect the vertical projection of the stress direction vector and strength on the surface in the stress field,consistent with the experimental results.Whether it can eff ectively refl ect the stress field requires further analysis of the specific situation of the local medium and the movement mode of the stress field.
基金supported by the National Key R&D Program of China(2021YFD2100400,2023YFE0104900)Xinjiang Agriculture Research System-Oil Crop Research System,China(XJARS-05)+3 种基金Taishan Industrial Experts Programme,China(tscx202306075)the Scientific and Technological Assistance Projects to Developing Countries,China(KY202201003)the Agricultural Science and Technology Innovation Program,Institute of Food Science and Technology,Chinese Academy of Agricultural Sciences(CAAS-ASTIP-2024-IFST)The authors are grateful for the financial support from the Arawana Charity Foundation,China.
文摘Peanut varieties are diverse globally,with their characters and nutrition determining the product quality.However,the comparative analysis and statistical analysis of key quality indicators for peanut kernels across the world remains relatively limited,impeding the comprehensive evaluation of peanut quality and hindering the industry development on a global scale.This study aimed to compare and analyze the apparent morphology,microstructure,single-cell structure,engineering and mechanical properties,as well as major nutrient contents of peanut kernels from 10 different cultivars representing major peanut-producing countries.The surface and cross-section microstructure of the peanut kernels exhibited a dense“blocky”appearance with a distinct cellular structure.The lipid droplets were predominantly spherical with a regular distribution within the cells.The single-cell structure of the kernels from these 10 peanut cultivars demonstrated varying morphologies and dimensions,which exhibited correlations with their mechanical and engineering properties.Furthermore,the mass loss versus temperature profiles of the peanut kernels revealed five distinct stages,corresponding to moisture loss,volatile loss,protein denaturation,and the degradation of various biomacromolecules.Variations were also observed in the lipid,protein,and sucrose contents,texture,bulk density,true density,porosity,geometric mean diameter,and sphericity among the diferent peanut varieties.This study establishes relationships and correlations among microstructure,engineering properties,and nutritional composition of commonly grown peanut varieties in major peanut-processing countries.The findings provide valuable insights into peanut quality evaluation,empowering the peanut industry to enhance their processing and product development efforts.
文摘The study focuses on the filling of pods from ten cacao clones originating from French Guiana in Côte d’Ivoire. Two reference clones (IFC5 and NA32) were used as controls. The parameters studied include the number of ovules per ovary, the average number of beans per pod, the fresh bean weight, and the pod index. The aim was to evaluate the genetic variability and agronomic performance of these clones under natural pollination conditions. The results show significant genetic variability between the clones for all traits studied. The IFC5 clone, known for its excellent pod filling, exhibited the highest apparent fertility (0.91), while the GU183/A clone had the lowest filling (0.47). Three types of distributions of the number of beans per pod were identified: a right-skewed unimodal distribution, characteristic of well-filled clones;a left-skewed unimodal distribution, associated with poorly filled clones;and an intermediate bimodal distribution. These differences could be related to pollination compatibility and the availability of compatible pollen. Regarding the fresh bean weight and pod index, the GU183/A clone stood out with the heaviest beans (3.27 g) but had a high pod index (49.58), indicating relatively low productivity. None of the Guyanese clones achieved the filling level of the IFC5 clone, although some surpassed the NA32 control. This study highlights the importance of apparent fertility and the number of beans per pod as essential criteria for cacao genetic improvement programs. The authors recommend extending research to a larger number of Guyanese clones and exploring complementary traits, such as the influence of pollination type and intergroup compatibility.
基金National Natural Science Foundation of China(No 52174048).
文摘Taking the Qihe area as an example,this paper compared various geophysical exploration methods in view of the problems of urban construction,deep thermal reservoir burial,and vast overlying low-resistance shield layer in deep karst geothermal exploration.A Controlledsource audio magnetotelluric(CSAMT)method was taken to overcome the problems and detect deep stratigraphic structures in the study area.The acquisition parameters of CSAMT were optimized to take into account the exploration depth and signal-to-noise ratio.The distortion of data in the near and transition zone was eliminated by the inversion of equivalent whole-region apparent resistivity,so as to achieve the purpose of deep sounding.Based on the resistivity profile resulting from the proposed CSAMT method,three faults were inferred and one low-resistance anomaly zone in the area was traced.The results of the profile interpretation were verified by drilling.The inferred stratigraphic boundaries and low-resistance anomaly zone were basically in agreement with the drilling results,thereby proving the eff ectiveness of the CSAMT method for deep geothermal exploration in low-resistance coverage areas.This method could provide technical support for deep geothermal exploration in similar areas.
基金supported by the National Natural Science Foundation of China(Nos.32171533 and 31971444)Anhui Provincial Natural Science Foundation(No.2208085J28)。
文摘Insect herbivory is ubiquitous in various ecosystems,and directly influences the growth and survival of individual plants,especially during their vulnerable early life stages like the seedling phase.This,in turn,exerts a significant influence on forest community diversity and structure,as well as ecosystem function and stability.Notable variation in herbivory has been detected both among and within plant species.For decades,many hypotheses have been proposed to explain such variations,including both biotic and abiotic variables.However,most studies have considered only one or several of these hypotheses by focusing on a few potential variables,and their results were usually inconsistent;thus,the factors driving herbivory remain unclear.In this study,we examined leaf herbivory by insects of woody species seedlings in a subtropical forest in southwestern China over two seasons.In total,24 potential variables that represented abiotic resource availability,characters of individual seedlings,conspecific and heterospecific species,and the whole seedling community were selected to test several commonly discussed alternative herbivory hypotheses.Overall,our findings showed that the plant apparency hypothesis was more supported than the other hypotheses in explaining insect seedling herbivory.Our results further indicated that the mechanisms and causes of insect herbivory are complex,multifactorial,species-specific and vary with seasons,indicating that there may be no uniform rules in explaining herbivory for all seedlings.Consequently,such complexity may play an important role in promoting species coexistence and biodiversity maintenance in seedling communities,which may further translate into the following generation of saplings or even adult communities.Changes in the community of insect herbivores and/or variables influencing insect herbivory,may disrupt stability of the original seedling community,thus affecting the regeneration and development of the entire forest community.Therefore,we suggest that issues related to insect herbivory should be considered when developing forest management and conservation.
基金funded by the HiGa project,supported within the Green Era Hub call by the Green Development and Demonstration Programme,GUDP,under the Ministry of Food,Agriculture and Fisheries of Denmark,the Flanders Innovation&Entrepreneurship(VLAIO)the Italian Ministry of Agriculture,Food Sovereignty and Forests(CUP:D23 C23000570005).
文摘Background Scant information is currently available on the use of insect oils in ruminant diets.Insect oils could be used as alternatives to certain conventional plant lipid sources that are considered no longer sustainable.This trial aims at evaluating the effects of the dietary inclusion of Hermetia illucens oil(HIO)vs.hydrogenated palm fat(HPF)on digestive parameters,oxidative stress,and milk production performance of dairy cows.Results Twenty-six Valdostana Red Pied cows were randomly divided into two groups and fed with hay ad libitum and a concentrate containing 3%(as fed)of either HPF or HIO.The trial lasted 50 d,including two weeks of diet adaptation.Individual feed intake and milk yield were monitored three and four times a week,respectively.Fecal samples were collected at the end(d 50)of the trial to determine total-tract nutrients apparent digestibility.Individual blood samples were collected to evaluate blood plasma metabolites(d 0 and d 50)and oxidative stress parameters(d 0,d 26 and d 50).Milk samples were collected at d 0,d 14,d 26,d 38 and d 50 for chemical composition analysis.Feed efficiency was estimated through feed conversion ratio and residual feed intake(RFI).Data were analyzed by SAS software using a mixed model.The diet had no effect on nutrients intake and apparent total-tract digestibility.However,the dietary inclusion of HIO led to higher milk production(+0.82 kg/cow/d;P<0.05)and slightly lower RFI(−0.008;P<0.001)when compared to the HPF diet.Milk composition and the nutritional metabolic status of the cows remained unaffected by diet.Serum antioxidant capacity was comparable between the two groups,while lower derivatives of reactive oxygen metabolite concentrations were observed in the HIO-fed cows when compared to the HPF-fed ones(−37.13 Carratelli Units;P<0.001).Conclusions The dietary inclusion of HIO instead of HPF did not negatively affect feed palatability and total-tract apparent digestibility of nutrients in dairy cows.Furthermore,it increased feed efficiency by supporting a higher milk production together with an improved antioxidant status.The results suggest that HIO could be an eligible option as an innovative energy source for dairy cows.
文摘The article discusses the use of pulse-width modulation signals to generate low-temperature atmospheric plasma in an inert gas environment.The results of studies of the energy consumption of a low-temperature plasma generation system depending on the duty rate,as well as the pulse repetition rate,are presented.The operating modes of the system have been established,in which a minimum of energy consumption is achieved.The issues of evaluating the interaction of plasma with objects based on the analysis of changes in signal parameters in the high-voltage circuit of the generator are also considered.
文摘The discovery of high-temperature superconductivity in La_(3)Ni_(2)O_(7) and La_(4)Ni_(3)O_(10) under pressure has garnered extensive attention.Herein,we report systematic investigations on the structure,magnetism,and electrical resistance evolutions of Pr_(4)Ni_(3)O_(10−δ)polycrystalline samples under various pressures.Pr_(4)Ni_(3)O_(10−δ)exhibits density wave transitions on Ni and Pr sublattices at approximately 157.6 and 4.3 K,respectively.The density wave can be progressively suppressed by pressure.A structural transformation from the monoclinic P21/a space group to the tetragonal I4/mmm occurs around 20GPa.An apparent drop in resistance with an evident magnetic field dependence is observed at pressures above 20GPa,indicating the emergence of superconductivity.The discovery of superconductivity in Pr_(4)Ni_(3)O_(10−δ)broadens the family of nickelate superconductors.Pr_(4)Ni_(3)O_(10−δ)provides a new platform for investigation of the mechanisms of superconductivity in the Ruddlesden-Popper phases of nickelates.
基金jointly supported by the projects of the China Geological Survey(DD20230092,DD20201119)。
文摘Catastrophic geological disasters frequently occur on slopes with obliquely inclined bedding structures(also referred to as obliquely inclined bedding slopes),where the apparent dip sliding is not readily visible.This phenomenon has become a focal point in landslide research.Yet,there is a lack of studies on the failure modes and mechanisms of hidden,steep obliquely inclined bedding slopes.This study investigated the Shanyang landslide in Shaanxi Province,China.Using field investigations,laboratory tests of geotechnical parameters,and the 3DEC software,this study developed a numerical model of the landslide to analyze the failure process of such slopes.The findings indicate that the Shanyang landslide primarily crept along a weak interlayer under the action of gravity.The landslide,initially following a dip angle with the support of a stable inclined rock mass,shifted direction under the influence of argillization in the weak interlayer,moving towards the apparent dip angle.The slide resistance effect of the karstic dissolution zone was increasingly significant during this process,with lateral friction being the primary resistance force.A reduction in the lateral friction due to karstic dissolution made the apparent dip sliding characteristics of the Shanyang landslide more pronounced.Notably,deformations such as bending and uplift at the slope’s foot suggest that the main slide resistance shifts from lateral friction within the karstic dissolution zone to the slope foot’s resistance force,leading to the eventual buckling failure of the landslide.This study unveils a novel failure mode of apparent dip creep-buckling in the Shanyang landslide,highlighting the critical role of lateral friction from the karstic dissolution zone in its failure mechanism.These insights offer a valuable reference for mitigating risks and preventing disasters related to obliquely inclined bedding landslides.
基金supported by the National Natural Science Foundation of China(Nos.U22A20160,82221003,81991505,82201123)China Postdoctoral Science Foundation(2022M720290,2021M700279)Hubei Provincial Key Laboratory of Oral and Maxillofacial Development and Regeneration Open Fund(2022kqhm004).
文摘Bone tissue renewal can be enhanced through co-transplantation of bone mesenchymal stem cells(BMSCs)and vascular endothelial cells(ECs).However,there are apparent limitations in stem cell-based therapy which hinder its clinic translation.Hence,we investigated the potential of alternative stem cell substitutes for facilitating bone regeneration.In this study,we successfully prepared cell membrane vesicles(CMVs)from BMSCs and ECs.The results showed that BMSC-derived cell membrane vesicles(BMSC-CMVs)possessed membrane receptors involved in juxtacrine signaling and growth factors derived from their parental cells.EC-derived cell membrane vesicles(EC-CMVs)also contained BMP2 and VEGF derived from their parental cells.BMSC-CMVs enhanced tube formation and migration ability of hUVECs,while EC-CMVs promoted the osteogenic differentiation of hBMSCs in vitro.Using a rat skull defect model,we found that co-transplantation of BMSC-CMVs and EC-CMVs could stimulate angiogenesis and bone formation in vivo.Therefore,our research might provide an innovative and feasible approach for cell-free therapy in bone tissue regeneration.
基金supported by the National Key R&D Program of China(No.2022YFD1700605)the National Natural Science Foundation of China(Nos.31872177 and31972511)the Fundamental Research Funds for Central Non-profit Scientific Institution,China(No.1610132-023005)。
文摘The creation of controlled-release urea (CRU) is a potent substitute for conventional fertilizers in order to preserve the availability of nitrogen (N) in soil,prevent environmental pollution,and move toward green agriculture.The main objectives of this study were to assess the impacts of CRU’s full application on maize production and to clarify the connection between the nutrient release pattern of CRU and maize nutrient uptake.In order to learn more about the effects of CRU application on maize yields,N uptake,mineral N (N_(min)) dynamics,N balance in soil-crop systems,and economic returns,a series of field experiments were carried out in 2018–2020 in Dalian City,Liaoning Province,China.There were 4 different treatments in the experiments:no N fertilizer input (control,CK);application of common urea at 210 kg ha^(-1)(U),the ideal fertilization management level for the study site;application of polyurethane-coated urea at the same N input rate as U (PCU);and application of PCU at a 20% reduction in N input rate (0.8PCU).Our findings showed that using CRU (i.e.,PCU and 0.8 PCU) may considerably increase maize N absorption,maintain maize yields,and increase N use efficiency (NUE) compared to U.The grain yield showed considerable positive correlations with total N uptake in leaf in U and 0.8 PCU,but negative correlations with that in PCU,indicating that PCU caused excessive maize absorption while 0.8 PCU could achieve a better yield response to N supply.Besides,PCU was able to maintain N fertilizer in the soil profile 0–20 cm away from the fertilization point,and higher N_(min)content was observed in the 0–20 cm soil layer at various growth stages,particularly at the middle and late growing stages,optimizing the temporal and spatial distributions of N_(min).Additionally,compared to that in U,the apparent N loss rate in PCU was reduced by 36.2%,and applying CRU (PCU and 0.8 PCU) increased net profit by 8.5% to 15.2% with less labor and fertilization frequency.It was concluded that using CRU could be an effective N fertilizer management strategy to sustain maize production,improve NUE,and increase economic returns while minimizing environmental risks.
基金the National Natural Science Foundation of China(Grant Nos.12102372 and 11872324)the Open Research Fund of CNMGE Platform&NSCC-TJ(Grant No.CNMGE2023011).
文摘Stress-dependent permeability models are developed for the organic pores and inorganic cleats/fractures in unconventional gas reservoirs,which are modeled as Biot’s porous media of dual-porosity.Further considering multiple flow mechanisms such as dynamic effects of gas flow and surface diffusion,apparent permeability models are obtained to investigate the characteristics of unconventional gas migration.Compared to the gas transfer in single-porosity reservoirs,the gas migration ability of cleats in dual-porosity stratums rarely changes while that of organic pores is greatly improved because cleats sustain major geomechanical shrinkage deformation when the pore pressure drops.Further,the mass flux of reservoirs is dominated by the mass flux of cleats,which has a lower peak value,but a much longer production term than those in single-porosity reservoirs due to the interaction between organic pores and cleats.Parametric analysis is conducted to identify key factors significantly impacting mass flux in unconventional reservoirs.Reasons for the mass flux variation are also explored in terms of gas migration ability and pore pressure distribution.
文摘Prostate cancer(PCa)imaging forms an important part of PCa clinical management.Magnetic resonance imaging is the modality of choice for prostate imaging.Most of the current imaging assessment is qualitative i.e.,based on visual inspection and thus subjected to inter-observer disagreement.Quantitative imaging is better than qualitative assessment as it is more objective,and standardized,thus improving interobserver agreement.Apart from detecting PCa,few quantitative parameters may have potential to predict disease aggressiveness,and thus can be used for prognosis and deciding the course of management.There are various magnetic resonance imaging-based quantitative parameters and few of them are already part of PIRADS v.2.1.However,there are many other parameters that are under study and need further validation by rigorous multicenter studies before recommending them for routine clinical practice.This review intends to discuss the existing quantitative methods,recent developments,and novel techniques in detail.
基金supported by the National Natural Science Foundation of China(52274056,U22B2075).
文摘Oil transport is greatly affected by heterogeneous pore–throat structures present in shale.It is therefore very important to accurately characterize pore–throat structures.Additionally,it remains unclear how pore–throat structures affect oil transport capacity.In this paper,using finite element(FE)simulation and mathematical modeling,we calculated the hydrodynamic resistance for four pore–throat structure.In addition,the influence of pore throat structure on shale oil permeability is analyzed.According to the results,the hydrodynamic resistance of different pore throat structures can vary by 300%.The contribution of additional resistance caused by streamline bending is also in excess of 40%,even without slip length.Fur-thermore,Pore–throat structures can affect apparent permeability by more than 60%on the REV scale,and this influence increases with heterogeneity of pore size distribution,organic matter content,and organic matter number.Clearly,modeling shale oil flow requires consideration of porous–throat structure and additional resistance,otherwise oil recovery and flow capacity may be overestimated.
基金supported by the Starting Grants of Institute of Metal Research,Chinese Academy of Science(E255L401).
文摘Lightweight refractories for the working lining of high-temperature furnaces play an important role in the smelting of advanced steels and superalloys.To prepare lightweight refractories for the working lining of high-temperature furnaces,the synthesis of lightweight aggregates is the basis.Recently,the research on the synthesis of lightweight aggregates with high service temperature,low thermal conductivity,high strength,and good slag resistance has received widespread attention.The available literature on the synthesis of lightweight aggregates was summarized,including corundum,mullite,mullite-corundum,spinel,corundum-spinel,cordierite,cordierite-mullite,calcium hexaluminate,corundum-calcium hexaluminate,bauxite,magnesia,magnesia-based,and forsterite-based aggregates.Finally,the future development trend of lightweight aggregates was proposed.
文摘Using the typical characteristics of multi-layered marine and continental transitional gas reservoirs as a basis,a model is developed to predict the related well production rate.This model relies on the fractal theory of tortuous capillary bundles and can take into account multiple gas flow mechanisms at the micrometer and nanometer scales,as well as the flow characteristics in different types of thin layers(tight sandstone gas,shale gas,and coalbed gas).Moreover,a source-sink function concept and a pressure drop superposition principle are utilized to introduce a coupled flow model in the reservoir.A semi-analytical solution for the production rate is obtained using a matrix iteration method.A specific well is selected for fitting dynamic production data,and the calculation results show that the tight sandstone has the highest gas production per unit thickness compared with the other types of reservoirs.Moreover,desorption and diffusion of coalbed gas and shale gas can significantly contribute to gas production,and the daily production of these two gases decreases rapidly with decreasing reservoir pressure.Interestingly,the gas production from fractures exhibits an approximately U-shaped distribution,indicating the need to optimize the spacing between clusters during hydraulic fracturing to reduce the area of overlapping fracture control.The coal matrix water saturation significantly affects the coalbed gas production,with higher water saturation leading to lower production.
基金The authors gratefully acknowledge financial support by the National Natural Science Foundation of China-Xinjiang Joint Fund(U2003124)the National Natural Science Foundation of China(No.51974001)the University Outstanding Young Talents Funding Program(No.gxyq2019016).
文摘Due to the instability of FeO at temperatures below 843 K,the fuidization reduction pathway of iron ore powder changes with the reduction temperature.Thus,the effect of temperature and reaction pathway interaction on the kinetics of fuidization reduction of iron ore powder under low-temperature conditions ranging from 783 to 903 K was investigated to describe the fluidization reduction rate of iron ore powder from three aspects:microstructure change,reaction limiting link,and apparent activation energy of the reaction,exploring their internal correlation.The experimental results revealed that in a temperature range of 783-813 K,the formation of a dense iron layer hindered the internal diffusion of reducing gas,resulting in relatively high gas diffusion resistance.In addition,due to the differences in limiting links and reaction pathways in the intermediate stage of reduction,the apparent activation energy of the reaction varied.The apparent activation energy of the reaction ranged from 23.36 to 89.13 kJ/mol at temperature ranging from 783 to 813 K,while it ranged from 14.30 to 68.34 kJ/mol at temperature ranging from 873 to 903 K.
